An update to the existing Haswell 4th Generation Core processors will be hitting retail sometime in mid-2014 according to what Intel has just told us. This new version of the existing processors will include new CPU packaging and the oft-requested improved thermal interface material (TIM). Overclockers have frequently claimed that the changes Intel made to the TIM was limiting performance; it seems Intel has listened to the community and will be updating some parts accordingly.
Recent leaks have indicated we'll see modest frequency increases in some of the K-series parts; in the 100 MHz range. All Intel is saying today though is what you see on that slide. Overclocks should improve with the new thermal interface material but by how much isn't yet known.
These new processors, under the platform code name of Devil's Canyon, will target the upcoming 9-series chipsets. When I asked about support for 8-series chipset users, Intel would only say that those motherboards "are not targeted" for the refreshed Haswell CPUs. I would not be surprised though to see some motherboard manufacturers attempt to find ways to integrate board support through BIOS/UEFI changes.
Though only slight refreshes, when we combine the Haswell Devil's Canyon release with the news about the X99 + Haswell-E, it appears that 2014 is shaping up to be pretty interesting for the enthusiast community!